Do all hi-po camchains have endless link? Sure i saw one with a master link.
if they have a master clip or stakable link, then you can change camchain w/o splitting cases..
450 Honda had a stakable link, might be available..
My 305 SuperHawk has the cliip type link, which will fit a CB750 chain, but who's got the guts to use it in a 750? The link is still available last I looked, but the broken chain is not. So you buy an endless chain, cut it and put the link in.
YOu're right the CB450 had the stake link which is also still available, and somewhat more secure than the clip link, if one knows how to stake it. There was a Honda tool for doing that, but we just used a 1/4 inch chisle and put a star stake in the pin. We had to backstop the link so we could punch in the stake.
HOnda issued a bulletin after production ended on the 305 to stop using the clip link on the 305 and switch to the stake link. I still use the clip, never knew one to fail.
here's the stake link:

here's cutting an endless chain:

Here's the clip link:

After threading the new chain through wired to the old chain

(Thought some readers may like some pictures)